class MyBlockingQueue{
    private String[] elems = null;
    private int head = 0;
    private int tail = 0;
    private int size = 0;
    //准备锁对象
    private Object locker = new Object();
    public MyBlockingQueue(int capacity){
        elems = new String[capacity];
    }

    public void put(String elem) throws InterruptedException {
       synchronized (locker){
           //新的元素要放到tail指定的位置上
           while(size >= elems.length){
               //队列满了，后续需要让这个代码能够阻塞
               locker.wait();
           }
           elems[tail] = elem;
           tail++;
           if(tail>=elems.length){
               tail = 0;
           }
           size++;
           //入队成功之后唤醒
           locker.notify();
       }
    }
    public String take() throws InterruptedException {
        String elem = null;
       synchronized (locker){
           while (size==0){
               //队列空了，后续也需要让这个代码阻塞
               locker.wait();
           }
           //取出head位置的元素并返回
            elem = elems[head];
           head++;
           if (head >= elems.length){
               head = 0;
           }
           //这个代码很容易遗漏
           size--;
           //元素出队列成功之后，加上唤醒
           locker.notify();
           return elem;
       }
    }
}
public class demo1 {
    public static void main(String[] args) throws InterruptedException {
        MyBlockingQueue queue = new MyBlockingQueue(1000);
        //生产者
        Thread t1 = new Thread(()->{
            int n = 1;
            while(true){
                try {
                    queue.put(n+" ");
                    System.out.println("生产元素 "+n);
                    n++;
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
        });
        //消费者
        Thread t2 = new Thread(()->{
            while(true){
                try {
                    String n =  queue.take();
                    System.out.println("消费元素 "+n);
                    Thread.sleep(500);

                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
        });
        t1.start();
        t2.start();
    }
}
